Change twine references to be immediately preceded by the pip install

line

This ensures that the python that installs is the same python that
should execute the module (this sometimes isn't true on macOS because
the python.org installs that cibuildwheel makes take precedence over
the system versions)

Fix #266

examples/travis-ci-deploy-only.yml

@@ -23,7 +23,7 @@ env:
     # Note: TWINE_PASSWORD is set to a PyPI API token in Travis settings
 
 install:
-  - python3 -m pip install twine cibuildwheel==1.1.0
+  - python3 -m pip install cibuildwheel==1.1.0
 
 script:
   # build the wheels, put them into './wheelhouse'
@@ -31,4 +31,8 @@ script:
 
 after_success:
   # if the release was tagged, upload them to PyPI
-  - if [[ $TRAVIS_TAG ]]; then python3 -m twine upload wheelhouse/*.whl; fi
+  - |
+    if [[ $TRAVIS_TAG ]]; then
+      python3 -m pip install twine
+      python3 -m twine upload wheelhouse/*.whl
+    fi